Hydraulic pipe



(No Model.)

A. H. MoILVAIN. HYDRAULIC PIPE.

No. 459,227. Patented Sept. 8, 1891.

UNITED STATES PATENT Clarion..

ALFRED H. AWLICILUIIW, OF PHILADELPHIA, PENNSYLVANIA.

HYDRAULIC PIPE.

SPECIFICATION forming part of Letters Patent No. 459,227', datedSeptember 8, 1895..

Application liled May 8, 1891. Serial No. 392,062. (No model.l

T0 all whom, may concern:

Be it known that I, ALFRED Il. MCILVAIN, a citizen of the United States,and aresident of Philadelphia, in the county of Philadelphia and Stateof Pennsylvania, have invented certain new and usefulImprovements inHydraulic Pipe; and I do hereby declare that the following is a full,clear, and exact description ot' the invention, which will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying` drawings, which form a part ofthis specification, and in which- Figure l is a perspective view of asection of my improved hydraulic pipe. Fig. 2 is a cross-section of thesame, and Fig. 3 isaperspective view of the pipe with a portion of itsouter covering loosened and turned down at two corners.

Like letters of reference denote corresponding parts in all the figures.

This invention relates to pipe for hydraulic and other purposes of thattype which consists practically of two concentric pipes of cement orsimilar material, each incased in a jacket and one inserted within theother, so as to form a compound pipe, so to speak; and my iml'irovementconsistsin thepeculiarconstruction of the outside pipejacket, as will behereinafter more fully described and claimed.

Referring' to the accompanying' drawings, the letter A designates theinside pipe or conduit proper, which is made of hydraulic cement or itsequivalent, and surrounded by a casing or jacket B of sheet iron orothersuitable metal. Around this metallic jacket is molded a concentricpipe C, also of cement or some similar material, and this outside pipeis incased in a jacket D, composed of one or more thicknesses of paper,felt, vulcanized liber, or some other similar flexible substance whichis not affected to any appreciable extentbyeither heat or cold. Thisexterior jacket or covering D has its meeting edges dovetailed, as shownat d, so that the vdovetails along one edge will interlock with thedovetails along the other edge, as illustrated in Fig. l. In this mannerthe outside jacket is not only made very stron and durable, but it isformed without any projecting seam or rib, being per'- fec-tly smoothand cylindrical and with a close and perfect joint. It desired, two ormore rows of rivets c may be driven through the outside jacket into thecement C while the same is yet in-a plastic state, so as to firmly unitethe cement pipe C to its jacket or cas-v ing D.

In practice I prefer to coat the insidejacket B with a thin layer ofcoal-tar, paint, or varnish for the twofold purpose of preserving itfrom rust and causing the better adhesion to itof the cement, which doesnot adhere well to smooth sheet-iron. Similarly, the outside jacket orenvelope D is coated or painted with a layer of some suitable varnish orcomposition which is impervious to water, or the material from whichthis outside jacket or envelope is made may be impregnated with asphalt,coal-tar, or some similar protective composition. i

I am aware that it is not new to construct a hydraulic pipe consistingof two concentric metallic shells with an inside cement lining andintermediate solid filling, as described and claimed in the patent toDaniel G. Phipps, No. 227,830, dated May 18, 1880; but. I have found byexperience that the alternate expansion and contraction ofthe outsidesheet-metal pipe due to heat in summer and frost in winter will sooncrack and disintegrate the intermediate filling, causing it to crumble,and thus sooner or later rendering it useless. This Ietliectuallyavoidby makingthisoutside jacket or casing of some elasticmaterial which is not affected by changes in the temperature, therebyadding greatly to the lite and eiciency of the pipe.

Having thus described my improvement, I claim and desire to secure byLetters Patent of the United Statesl. As an improvement in hydraulicpipe, the herein-described compound pipe comprising the inside cementpipe or conduit A, having metallic jacket B, in combination with theoutside casing-pipe C, of cement or similar material, having a jacketDort` one or more layers of paper, felt, or analogous material notappreciably affected by changes in the temperature, substantially as and for the purpose shown and set forth.

2. In a compound pipe of the described construction, the outsidewaterproof jacket or Io vided with rivets c, projecting` through thejacket into the casing-pipe, substantially as and for the purpose shownand set forth.

In testimony that I claim the foregoing as my oWnI have hereunto affixedmy signature in presence of two Witnesses.

ALFRED H. MCILVAIN. Vtnesses:

J No. W. BOILEAU, W. G. RoLTs.

